Table 3.
Analytic Sequence Using the Rasch Partial Credit Model
| Iteration | Items | Rating scale categories | Person mean (SD) logits | RMSE | Adj. SD | SI | PSR | Wright's PSR | Number of misfitting items | PCAR Eigenvalue 1st contrast (%) | Ceiling effect n (%) | Floor effect n (%) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 1. Calibration sample, 252 participants | 6 | 29 | -0.35 (1.98) | 0.75 | 1.83 | 2.43 | 0.86 | 0.95 | 0 | 1.63 (8.1) | 22 (8.7) | 0 |
| 2. Validation sample, 252 participants | 6 | 29 | -0.15 (1.82) | 0.72 | 1.67 | 2.33 | 0.84 | 0.95 | 0 | 1.71 (9.1) | 18 (7.1) | 0 |
| 3. Validation sample, 252 participants, anchored | 6 | 29 | -0.13 (1.89) | 0.74 | 1.74 | 2.35 | 0.85 | 0.95 | 0 | 1.74 (9.5) | 18 7.1) | 0 |
| 4. Full sample, 1442 records, qnchored | 6 | 29 | -0.44 (1.75) | 0.72 | 1.59 | 2.20 | 0.83 | 0.95 | 0 | 1.61 (8.8) | 71 (4.9) | 1 (0.1) |
SD, standard deviation; RMSE, root mean square standard error; SI, separation index; PSR, person separation reliability; PCAR, Principal Components Analysis of Residuals.